This study is being done to find out how age, activity level, and the presence of heart disease affect the way the body controls blood pressure. A total of 80 individuals will be recruited for the study, and will consist of two groups: sedentary healthy individuals and those with coronary artery disease (CAD). Each group will undergo screening tests, including history, questionnaires, physical exam, lab tests, treadmill exercise tolerance test, and maximal exercise test. These screening tests will be repeated at 3 months and 6 months.